DDA Line drawing

gistfile1.js

function line( xa,ya, xb,yb ) {
	dx = xb - xa;
	dy = yb - ya;
	
	if( dx < 0 ) {
		cInc = -1;
	} else {
		cInc = 1;
	}
	if( dy < 0 ) {
		rInc = -1;
	} else {
		rInc = 1;
	}
	
	if( Math.abs( dx ) >= Math.abs( dy ) ) {
		
		m = dy / dx;
		if( m < 0 ) {
			m = -m;
		}
		
		h = 0;
		c = xa;
		r = ya;
		console.log('plot',c,r);
		for( i = Math.abs( dx ); i > 0; i-- ) {
			c += cInc;
			h += m;
			if( h > .5 ) {
				r += rInc;
				h -= 1;
			}
			console.log('plot',c,r);
		}
		
	} else {
		
		m = dx / dy;
		if( m < 0 ) {
			m = -m;
		}
		
		h = 0;
		c = xa;
		r = ya;
		console.log('plot',c,r);
		for( i = Math.abs( dy ); i > 0; i-- ) {
			r += rInc;
			h += m;
			if( h >= .5 ) {
				h -= 1;
				c += cInc;
			}
			console.log('plot',c,r);
		}
		
	}
}

//line(8,3, 1,1);
//line(-7,3, -1,1);
//line(1,-1, 3,-6);
//line(-7,-2, -1,1);